One vertex per element, one color per generator, with an edge from x to x·s.
(1,2,4,6)(3,7,8,5)(9,10,13,14)(11,12,15,16)(17,18,21,20)(19,22,23,24)(25,26,30,27)(28,33,35,31)(29,32,38,34)(36,40,37,39)(3,8)(5,7)(9,11,13,15)(10,12,14,16)(19,23)(22,24)(26,27)(28,35)(32,34)(36,37)(1,3)(2,5)(4,8)(6,7)(9,12)(10,11)(13,16)(14,15)(17,19)(18,22)(20,24)(21,23)(25,27,30,26)(28,33,35,31)(29,32,38,34)(36,39,37,40)(1,3)(2,5)(4,8)(6,7)(9,11)(10,12)(13,15)(14,16)(25,28)(26,31)(27,33)(29,37)(30,35)(32,40)(34,39)(36,38) involution — undirected(1,2)(3,5)(4,6)(7,8)(9,10)(11,12)(13,14)(15,16)(17,20,21,18)(19,24,23,22)(25,29)(26,32)(27,34)(28,36)(30,38)(31,39)(33,40)(35,37)A Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.